Adding trailer brake module help

I need to add a trailer brake to my 85 4wd 5.0 AOD
Any help on what works best

I've used the Tekonsha 90195 P3 from Amazon.  They work well, but are a bit pricey.  However, I'm happy pay a bit more for reliable brakes, and these have been reliable.

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does this work off the brake light?
so  Im asumming it has one pressure preset and add more by hand if needed?

It works off the brake light and a pendulum.  And there's a dial for preset.  Hook the trailer up, get up to about 15 MPH, and hit the lever on the controller.  You want the trailer's brakes to come close to lockup when you pull the lever all the way.  Dial in more or less preset and you are set.

Gary, I will be adding a brake controller to my truck soon so this was a timely post. I have never heard of Tekonsha before. I took a look at it on Amazon. You reference the lever, which most of them that I have looked at have on the front of them. But I don't see a lever on the Tekonsha unit. Is it just not obvious in the photos, or does it not have one?

It is down below and you can't see it from above.  But you can here:

Unfortunately you can't get the real good ones any more, they aren't compatible with anti-lock brakes. I still have one I bought for my 1977 F150.

To generalize it a bit, there are two main types of brake controllers:  timer and accelerometer.

The timer style only goes off the brake light.  As soon as the brake light goes on the brake controller starts ramping up the voltage to the trailer brakes.  You can set the ramp rate and the max voltage that it goes to, but once set that's what you get (unless you reset of course).  So whether you are gradually slowing down for the stop sign at the bottom of a freeway off ramp or in a panic stop you get the same ramp rate up to the same maximum brake level.  You can override it and apply more brake faster with the manual lever, but as far as automatic use you get the same thing all the time.

The accelerometer style (sometimes called a proportional controller) also only has the brake light as a signal into the unit, but internally it has an accelerometer.  So once the brake lights come on it looks at how quickly the truck is decelerating and applies the trailer brakes proportionally.  So you get light application of the trailer brakes if you are slowing down gradually and hard application if you are slowing down hard.

The timer style is the cheapest, and has the obvious disadvantage of not being possible to dial in.  Either it comes on too aggressively for most stops (which you deal with by letting off the brakes briefly to start the cycle over again) or too lightly for panic stops (which you can deal with by applying the trailer brakes by hand).  I used to work with a guy who loved this style because it gave him perfect control.  He set the max braking level as low as possible so there was essentially no automatic application of the trailer brakes, and always worked the controller by hand so he could get exactly the braking he wanted.  He is an exception, but I mention him because he's not wrong.  But most people I know (including me) think the timer brakes controllers are pure garbage, so I don't personally recommend them.

The accelerometer style has the POTENTIAL downside of getting into a weird feedback loop.  As it senses deceleration it applies the trailer brakes harder, which makes the truck/trailer decelerate harder, which makes it apply the trailer brakes harder, which makes it decelerate harder....  It certainly makes sense that this would happen, but I say "potential" as this doesn't seem to actually be a problem.  It seems like it would be more likely with a very heavy trailer (where the trailer brakes are more significant that the truck brakes).  But I've never actually noticed it with trailers up to about the same weight as the truck.  But I mention it because if you are thinking about a HEAVY trailer you might want to get advice from someone who has experience there.

The Tekonsha controller Gary mentions is the accelerometer style, and I believe him that it's a good one.  Personally I've never paid over about $80 for a proportional brake controller, and I've always been happy with what I've bought.  That Tekonsha might be well worth the added cost to some people, but you can get a "good enough" controller a lot cheaper.  The cheaper ones do need to be mounted straight fore-and-aft in the vehicle and adjusted for how far off level they are for the accelerometer to work correctly, while I believe some of the more expensive ones have multi-axis accelerometers that automatically compensate for the mounting angle.  But that's just ease of installation.  Once installed and set properly the cheap ones work well in my experience.


There is another style that I've used.  I think the brand was Jacobs, and it had a cable that went to the brake pedal.  The farther you pushed the brake pedal the harder it applied the trailer brakes.  It let you adjust the gain so it could apply brakes more or less aggressively.  That was a little harder to install, and I never see them advertised, so I don't include it as a mainstream option.  But it did work well for me.

Good explanation, Bob.  I wasn't aware of how the timer-style controllers actually work.

And yes, my Tekonsha adjusts for how it is installed in the vehicle.  Which is good as it frequently gets installed at a different angle since it has to come off to get to other things on/under the dash.  But that has not changed its performance at all.

Speaking of performance, it has done everything I could ask of it.  I pulled the 25' Sea Ray's aluminum trailer empty with it and was easily able to adjust it to not quite lock up all four wheels on the trailer with no load or with the boat on.  Ditto for the car hauler trailer, although the light/loaded difference wasn't as dramatic since the trailer is steel and heavy by itself.

As for the feedback loop, I've not seen that.  And I've had the car hauler trailer loaded to where it weighs more than the truck.  But stops were always well controlled with no glitches at all.

I'm not saying that Tekonsha is the way to go.  It is just that it is the only one I've installed and used.  But it has always worked very well.  And I will admit that when it comes to safety I'll gladly pay a bit (a lot?) more.

As for braking by hand, no way, Jose!  I know of at least one case where I'd have been in an accident long before I could have thought "I need trailer brakes NOW" and gotten my hand on the controller at the same time as getting my foot on the truck brake pedal.  (I was in the left lane and a car cut in front of me and immediately hit the brakes to turn into a business.  I KNEW I had him, but the controller did its thing and we stopped just short of his rear bumper.)  Maybe others can think and move that fast, but not me.

Gary Lewis wrote

....  And yes, my Tekonsha adjusts for how it is installed in the vehicle.  Which is good as it frequently gets installed at a different angle since it has to come off to get to other things on/under the dash.  But that has not changed its performance at all....

All the (cheap) proportional brake controllers I've bought had to be mounted straight in line with the vehicle, but could be angled up or down.  Then an adjustment screw needed to be turned to make a line on the dial horizontal, which evidently turned the accelerometer so it was lined up correctly.  But when I looked at the owners manual I just Googled for the controller that came in my Dodge it says it has a 3-axis accelerometer which automatically accounts for differences in mounting angles.  So far I haven't been successful using that controller, but I think it's just because I didn't know how to adjust it.  So the jury is still out on that as an example of the 3-axis accelerometer

Gary Lewis wrote

....  As for braking by hand, no way, Jose!  I know of at least one case where I'd have been in an accident long before I could have thought "I need trailer brakes NOW" and gotten my hand on the controller at the same time as getting my foot on the truck brake pedal.  (I was in the left lane and a car cut in front of me and immediately hit the brakes to turn into a business.  I KNEW I had him, but the controller did its thing and we stopped just short of his rear bumper.)  Maybe others can think and move that fast, but not me.

I agree with you on this (and so do most people).  But I'm not going to say that it didn't work for this guy I knew, so I mention it.  However I still don't recommend the timer style.

My Tekonsha doesn't have to be installed level front to rear, but it is supposed to be level side to side.  And it is supposed to be installed in line with the direction of travel, as shown in the instructions:

I had an accelerometer one in Darth when I bought him. I figured it's in here, the previous owner towed a big 5th wheel with him and the original owners towed large horse trailers.

I hit a rough area on US 17 in York County, a stop light, then a sweeping right curve then a major intersection beyond the curve, trailer dealer was beyond the second light. When I stepped on the brakes, the road is a bit rough there probably from tractor-trailers getting caught by the light. As a result the brake controller proceeded to go bang, bang, bang with the brakes (I had adjusted it previously on a smooth road for good braking).

I had towed the trailer up to the campground near Gordonsville VA with my 1977 F150, it pulled it fine, I just wasn't real comfortable with the brakes, nice new "non hazardous" vegetable lining since asbestos is bad for you. The rear shoes were well done by the time we got to the campground.

Gentleman next to the site I set the trailer up in had his truck for sale. My first reaction was "too big and unwieldy", I found, big yes, unwieldy, not once you learn the secrets, like going out straight then spinning the wheel all the way to full lock. Darth can make a U-turn in 2 lanes + the median of a divided 4 lane highway. I went back up to pick the trailer up (wife spent a week decompressing after quitting a stressful job) and looked at the truck, drove it, told the owner I would buy it and gave him a deposit. Went back up with my 17 year old son, payed the balance and received the signed Maine title, repaired the accelerator pump on the Holley 4180C (it wasn't working at all). Checked a few items, put the broken off piece of one fender in the back seat, hooked the Plymouth Horizon up with my tow bar and we headed home. Stopped in Crittenden VA to leave Darth so a good friend could repair the fenders. On the way I noticed that directional stability left a lot to be desired. Right tie rod was about to fall off, Ford in their infinite wisdom had rubber sockets at the ends of the tie rods. Lost 2 - 3 quarts of oil, Horizon found it! Oil filter adapter was loose.

While the fenders were being repaired, I replaced both tie rods. Once that was done I tweaked the brake controller then headed to the trailer dealer with our "punch list". That was when I found out the brake controller had a mind of it's own.

Bob vary well posted
I am also of the school that the timed ones are junk and should never be sold but who am I right?

I have installed a few controllers in different things over the years and none were timed.
I also never had any issues with the feed back of slowing and the controller slowing more, etc. on any of the cars or trucks we towed with.

The old school controller that hooked to a brake line was the bees knees but as said dose not play well with ABS brakes.

I have bought 1 of the brand Gary uses, (the others I dont remember the brands) one I bought thru Uhaul, 1 from Etrailer.com on line, and the last I picked up in Northern Tool for the 81 F100.
So far it has worked as it should when I pulled the car clubs 20 ft enclosed trailer 2 times and will tomorrow to a show.

Follow the instructions that come with the controller and you will be good.
Dave ----